Raise your hand if you believe the Harbaugh family storyline has been exhausted.

I believe we’ve heard from Mom and Pop Harbaugh, the brothers and the sister. Unless Manti Te’o proclaims he is now going steady with an imaginary Harbaugh sibling, I think that’s it.

No, wait, we haven’t revisited the story that former Bears quarterback Jim Harbaugh was working out in the old Halas Hall weight room when then-head wonk Michael McCaskey plopped down next to him and began working his, um, guns.

Moving right along, raise your hand if you’ve also had enough of the “Ray Lewis’ Last Game’’ storyline. Great player. Maybe the greatest of all time at his position. But I’m done with the idolatry and especially listening to the scriptural adoration from a man who pleaded guilty to obstruction of justice in a double-murder.

But suddenly there comes a storyline that just might become the X factor in the Super Bowl.

President Obama indicted the head-banging nature of the game by telling The New Republic that if he had a son, he would “have to think long and hard before I let him play football.’’

Obama’s concern centers on head injuries endemic to the game. Researchers recently discovered chronic traumatic encephalopathy -- CTE -- in brain scans of some living NFL players. CTE, a brain disease linked to head trauma, was discovered previously only in players who died. Most notably, doctors found CTE in the brain of Junior Seau, who committed suicide in May.

Seau’s family claimed the linebacker’s suicide was the result of the violent hits he delivered and received that went unregulated medically by the NFL. The family’s claim ties in with the class-action lawsuit of former NFL players who charge the league with hiding concussion dangers and other medical negligence and conspiracy involving head injuries.

Which brings me to my X factor for this Sunday’s game.

The Ravens' defense brings hellacious pressure from multiple launch points. You see kill shots the way the 1985 Bears defense manufactured. Indeed, the Ravens play with an old-school mentality.

But here’s the deal: It is exactly that old-school NFL mentality that is being sued for the massive hits. It’s is exactly that old-school NFL mentality that could face trebled damages hitting 10 figures.

Baltimore led the NFL with 11 personal foul penalties. Members of the Ravens defense alone racked up eight, more than any other team amassed total. The Ravens have a reputation, and it’s not the kind the NFL celebrates the way it did when Buddy Ryan’s defense obliterated 13 quarterbacks.

I can see how the thing the Ravens do the best mushrooms into the factor that hurts their Super Bowl chances the most. Given the pressure the NFl is feeling in courts of law and public opinion, I fully expect the league to instruct its officials to throw whatever flags are necessary to maintain relative safety in the Super Bowl. The perception of safety, anyway.

Eleven years ago, the Patriots upset the Rams by daring officials to throw flags on every play. New England’s nefarious Bill Belichick coached his defense to mug every Rams receiver in the “Greatest Show on Turf.’’ The Patriots’s game plan was to break whatever rules had to be broken, and then dare the officials to stop the biggest game on earth every 10 seconds.

Those officials could’ve. Those officials didn’t. These officials will.

That’s what I expect from the officials working Sunday’s game. High Lord&Master Roger Goodell actually needs the game stopped to march off personal foul calls for spearing and helmet-to-helmet contact just to show who’s in charge. Goodell needs to act like the owners’ concern for player safety is paramount, even though we know the only thing that matters is winning court cases.

This is the league’s biggest event -- heck, the sporting world’s biggest event. Everybody will be watching, including lawyers for the plaintiffs and members of the prospective jury pool. Better a flag on every play Sunday, the NFL probably feels, than a billion-dollar judgment later.

With that much money stake, I believe that kind of thinking will influence a game as big and as important as the Super Bowl. If so, then the vicious Ravens defense is in trouble. Strict officiating of marginal calls would extend San Francisco drives and force Baltimore’s defense to stay on the field. Like that, the Ravens would turn over field position and time of possession to a San Francisco team that punishes such mistakes with visits to the end zone.